Reed switch circuits



April 23, 1968 E. w. WERTS 3,379,863

REED SWITCH CIRCUITS Filed Dec. 50, 1964 5 Sheets-Sheet 1 INVENTOR 2 EVERETT W. WERTS BY in FM.

ATTORNEY April 23, 1968 E. w. WERTS 3,379,863

REED SWITCH CIRCUITS Filed Dec. 50, 1964 5 Sheets-Sheet 2 INVENTOR EVERETT w. WERTS 5AM M ATTORNEY April 23, 1968 E. w. WERTS 3,379,863

' REED SWITCH CIRCUITS Filed Dec. 30, 1964 5 Sheets-Sheet 3 INVENTOR EVERETT W. WERTS ATTOR NE Y April 23, 1968 E. w. WERTS 3,379,863

REED SWITCH CIRCUITS Filed Dec. 30, 1964 5 Sheets-Sheet 4 INVENTOR EVERETT W. WERTS ATTORNEY A ril 23, 1968 E. w. WERTS REED SWITCH CIRCUITS 5 Sheets-Sheet 5 Filed Dec. 30, 1964 OH g JM A B H v 0 VT 4 fi y H? T m y o ba j B 9 5% "NJ/W W gm yr g I! INVENTOR EVERETT W. WERTS FIGB ATTORNEY United States Patent Qflice Patented Apr. 23, 1968 3,379,863 REED SWITCH CIRCUliTS Everett W. Werts, Normal, Ill, assignor to General Electric Company, a corporation of New York Filed Dec. 30, 1964, Ser. No. 422,317 24 Claims. (Cl. 235-92) ABSTRACT OF THE DISCLGSURE Shift register and counting circuits in which each stage includes two latch-type double-throw reed switches. In each stage of the shift register the fixed contacts of one switch are connected to the control windings of the other switch. The fixed contacts of the other switch in one stage are connected to the control windings of the one switch in the next succeeding stage. In a binary counter the fixed contacts of the other switch are connected to the control windings of the one switch in the same stage with the connections transposed. Selected fixed contacts of the switches in one stage are connected to the movable contacts of switches in the next stage.

This invention relates generally to circuits formed from double-throw switches and, more particularly, this invention relates to shift registers and counting devices utilizing double-throw magnetic reed switch circuitry.

Prior to the advent of magnetic reed switches, circuit arrangements such as shift registers had been formed with electromechanical relay devices as primary switching elements. The circuits formed with conventional relays provided adequate results, but left room for much improvement. One of the disadvantages of electromechanical relays in a memory circuit is that they must be constantly energized or the signal stored in the relay is lost. Therefore, a power failure means the loss of all stored signals. Since the operation of a relay generally depends upon fairly close current tolerances, prior art circuits have the disadvantage that variations in power supply characteristics could vitally affect circuit operation, even if no complete power failure was involved. A further disadvantage of electromechanical relay circuits is that the loss of a memory-stored signal will depend upon the timing of the switching operation. This accurate timing requirement means more complex circuitry and less circuit reliability. Circuits built about electromechanical relays have added complexity because of the additional elements necessary to provide a memory characteristic. A reed switch with a permanent memory characteristic permits the elimination of the additional elements and provides for the construction of a complete circuit arrangement from a few basic units.

Previous circuits utilizing either electromechanical relays or magnetic reed switches have been plagued by the fact that switch contacts which make and break current have a greatly decreased life span. To prevent this deleterious effect the circuits of this invention do not have the current interrupted by the reed switches included in the basic circuits. Elimination of current making or breaking by the reed switches in the basic circuits also permits overcoming another switching problem-that of contact bounce. Another problem area in prior art circuits of the type included in this invention has been inductive coupling interference between control coils. These problems of the prior art are overcome in the present invention by utilizing the desirable characteristics of double-throw magnetic reed switches in unique circuit arrangements.

It is therefore a primary object of the present invention to provide novel and improved circuit arrangements based upon double-throw magnetic reed switches.

It is another object of this invention to provide simplitied circuitry that operates quickly, efiiciently, and reliably with a greatly increased life of circuit elements.

It is yet another object of this invention to provide circuit arrangements in which permanent memory characteristics independent of power failure are achieved without the inclusion of different types of circuit elements.

It is a further object of this invention to provide simple, reliable circuitry which is not critically dependent upon power supply magnitudes.

It is yet a further object of this invention to provide circuit arrangements which accomplish all desired functions without any inductive coupling interference between successive units.

Briefly, the circuitry of this invention is realized by using two sets of identical double-throw magnetic reed switches. All of the double-throw magnetic reed switches have a movable contacting element and :a pair of stationary contacts. The movable contacting element is always positioned on one or the other of these stationary contacts. A pair of control means, in the form of magnetic coils, is associated with each switch and controls the position of the movable contacting element. After the movable contacting element has been forceably transferred to one of the stationary contacts by one of the control means, permanent magnet biasing means hold the movable contacting element in that position until it is forceably transferred by the other control means to the other of the stationary contacts.

There are two basic forms of circuits utilizing these sets of switches. In each of the forms a switch from each of the sets of switches is placed in a single stage of the circuit. In the first form one of the stationary contacts of the switch in the first set is connected to one of the control means of the switch in the second set and the other stationary contact of the switch in the first set is connected to the other of the control means of the switch in the second set. Thus, the switch in the first set directly governs which of the control means of the switch in the second set will be energized. One of the stationary contacts of the switch in the second set is then connected to one of the control means of a switch in the first set in the next succeeding stage, with the other of the stationary contacts of the switch in the second set connected to the other control means of the switch in the first set in the next succeeding stage. Thus, by placing a number of these stages together, information may be transferred from stage to stage. The transmitting of information from a switch in the first set of switches to the switch in the second set of switches in the same stage, and from there to the next succeeding stage, is controlled by an additional switch which alternately energizes a selected control means of each of the switches in the first set of switches and a selected control means of each of the switches in the second set of switches.

In the second type of basic form the stationary contacts of the switch in the first set of switches are connected to the control means of the switch in the second set of switches, in the same manner as in the first form. However, each of the stationary contacts of the switch in the second set of switches is now connected to one of the control means of a switch in the first set of switches in the same stage, thereby forming a stage which is selfrepeating. To make this form work properly the connections from the stationary contacts of the switches in the second set to the control means of the switch in the first set are transposed, so that a resetting type of action is achieved. A plurality of stages of this type may be connected together by taking an output from a selected stationary contact and passing the signal to the next succeeding stage, where a device such as a binary counter may be formed. Both of these forms of circuit arrangements are based upon the concept of having a switch from each set of switches in every stage and connecting a series of stages together to form a desired circuit arrangement.

The novel and distinctive features of the invention are set forth in the appended claims. The invention itself, together with further objects and advatages thereof, may be undersood by reference to the following description and accompanying the drawings in which:

FIG. 1 is a schematic circuit diagram of a basic shift register;

FIG. 2 is a schematic circuit diagram of the basic shift register of FIG. 1 illustrating both forward and backward shifting;

FIG. 3 is a schematic circuit diagram of a simultaneous shift register;

FIG. 4 is a schematic circuit diagram of a sequence shift register;

FIG. 5 is a schematic circuit diagram of a ring counter;

FIG. 6 is a schematic circuit diagram of a flip-flop circuit formed from double throw reed switches;

FIG. 7 is a schematic circuit diagram of a binary counter, and

FIG. 8 is a schematic diagram of an add and subtract count register.

Referring now to FIG. 1, there is depicted a basic shift register circuit utilizing double-throw magnetic switches. The shift register includes a first set of double-throw reed switches indicated by the letter A, and a second set of double-throw reed switches indicated by the letter B. Each of the switches in the first set of switches has a movable contacting element 1, stationary contacts 3 and S, and control means 7 and 9. Contacting element 1 is always in either a first contacting position, when it contacts stationary contact 3, or in a second contacting position, when it contacts stationary contact 5. If the movable contacting element is contacting stationary contact 5, energization of the first control means 7 will forceably transfer the movable contacting element 1 to stationary contact 3. Similarly, if the contacting element 1 is positioned in contact with stationary contact 3, energization of the second control means 9 will cause the movable contacting element 1 to be forceably transferred to movable contacting element 5. Whichever of the stationary contacts movable contacting element 1 is positioned in contact with, a biasing means (not shown) retains the movable contact ing element 1 in that position until it is forceably transferred by control means 7 or control means 9 to the other position. This aspect of the switch is fully illustrated and discussed in U.S. Patent No. 3,166,652.

The switches in set B are identical to those described in set A and have a movable contacting element 11, stationary contacts 13 and 15, and control means 17 tnd 1). The first control means 17 forceably transfers contacting element 11 to stationary contact 13 and the second control means 19 forceably transfers the movable contacting element 11 to stationtry contact 15. As in the A switches, a biasing means (not shown) retains the movable contacting element 11 in whichever contacting position it is last placed by the control means 17 and 19.

Power for the circuit is obtained from a DC source and applied across lines 21 and 23. From FIG. 1 it may be seen that the movable contacting elements 1 of the switches in the first set of switches A and the movable contacting elements 11 in the second set of switches B are connected to line 21. Line 23 is connected to the movable contacting element 25 of a shift switch indicated generally at 27. Shift switch 27 also includes stationary contacts 29 and 31. Stationary contact 29 is connected to line 33 and stationary contact 31 is connected to line 35. One side of the first control means 7 of the switches in the set of switches A is joined to one side of the second control means 9 and this common side is then joined to line 35. Similarly, one end of first control means 17 is joined to one end of second control means 19 of the switches in the second set of switches and this common end is joined to line 33.

In operation, an input signal is applied to either the first control means 7 or the second control means 9 of the switch in the first set of switches in the first stage. This input signal has a polarity the same as that appearing on line 21, so that when the movable element 25 of switch 27 is thrown to stationary contact 31, known as the shift position, one of the control means of the switch in set A will be energized. Energization of one of the control means of the switch in the set of switches A causes movable contacting element 1 to be positioned in contact with either stationary contact 3 or stationary contact 5. Transferred of the movable contact element 25 of switch 27 to stationary contact 29, known as the set position, will cause one of the control means 17 and 19 of the switch in the second set of switches in the first stage to be energized from line 21 through movable contacting element 1 to line 33 and thence to line 23. This causes the input signal to be stored in the switch in the set of switches B. In this arrangement the switches in the first set of switches A act as input switches and the switches in the second set of switches B act as memory units and control the signal applied to the input switch of the next stage upon the occurrence of another shift operation Thus, the movement of movable contacting element 25 of the switch 27 between stationary contacts 29 and 31 causes an alternate energization of the control means of the switch in the first set of switches A and a control means of the switches in the second set of switch B. In addition, the connection of stationary contact 3 to control means 17, stationary contact 5 to control means 19, stationary contact 13 to control means 7, stationary contact 15 to control means 9, means that the energization of a particular control means is controlled by a switch from the other set of switches. In this manner alternate energization of lines 33 and 35 cause a signal to be transferred from a switch in the first set of switches A to a switch in the second set of switches B and back to a switch in the first of switches A in the next succeeding stage. By this procedure information is shifted from stage to stage until removed from the output.

During the operation of the shift register it is also possible to provide for energization of an output load, indicated as 37. This output load 27 is connected in parallel with a control means of one of the switches. With this arrangement the output load current is interrupted during each operation of switch 27, since it is connected to line 33, but the load current is not broken by the reed switches in the register, so that contact life is increased. Load 37 could be connected directly to line 23, in which case the load current would only be broken when the control means with which it is connected in parallel is not connected for energization, rather than upon every operation of switch 27. However, this arrangement has the disadvantage that the reed switch in the register would then make and break the load current and therefore decrease the life of the switches in the register.

It is sometimes desirable to obtain an indication of energization of a particular unit in the register. This may be achieved with the use of breakdown devices 39, which may be neon lamps. To achieve this indication an AC supply is introduced through transformer 41. Secondary 43 of transformer 4-1 has one side connected to line 33 and the other side connected to any of the desired breakdown devices. The other side of the breakdown devices is connected to a stationary contact in the shift register, such as stationary contact 5 of the switches in said first of switches A. When the movable contacting element 1 is positioned on stationary contact 5, and switch 27 is positioned with movable contact element 25 on stationary contact 29, the full DC potential is applied across the breakdown devices 39. However, this potential is less than the firing potential of the breakdown devices 39 so hat the devices 39 fire only when the half cycles of AC supplied from transformer 41 add with the DC voltage to exceed their firing potential.

FIG. 2 shows the same basic arrangement as FIG. 1, except that arrangements have been provided for producing backward shifting, as well as forward shifting. This additional function entails the inclusion of control means 45 and 47, corresponding respectively to control means 9 and 7, for the switches in said first set of switches A. While one side of control means 9 is connected to stationary contact of the switch in the second set of switches B in the preceding stage, one end of control means 45 is connected to stationary contact 15 of the switch in the second set of switches B in the succeeding stage. Of course, when a backward shifting operation is in process this would actually be a preceding stage for the signal being shifted backwardly. To provide for the backward shifting, an additional shift switch 49 is added to the circuit. A shift switch similar to switch 27 in the basic circuit, shift switch 27 has its movable contacting element positionable on either stationary contact 29' or stationary contact 31', which are connected to lines 33' and 35, respectively. Movable contacting element 25' of shift switch 27' is connected to stationary contact 51 of shift switch 49. During forward shifting the movable contacting element 53 of shift switch 49 is positioned on stationary contact 51 to provide the switching arrangement described in connection with shift switch 27. During backward shifting the movable contacting element 25' of switch 27' is positioned on stationary contact 31 to permit normal energization of control means 17 and 19 of the switches in the second set of switches B. The shift switch 49, though, includes an additional stationary contact 55 which is connected to an additional line 57. Line 57 is connected to the common ends of control means 45 and 47 in the same manner that line 33 is connected to the common ends of control means 7 and 9. The backward shift operation is then the same as the forward shift operation. Thus, both forward and backward shifting may be provided in the same unit by utilizing shift switch 27' when the forward shifting is desired and utilizing shift switch 49 when backward shifting is desired.

In FIG. 3 the basic system is shown as applied in a simultaneous shift register control system. The basic circuitry is the same as that shown and described in connection with FIG. 1 so that it need not be repeated here. An additional information handling channel has been added, but since each channel is identical in operation a discussion of one channel sufi'ices for all. One change in arrangement, that does not really change the circuit operation, is that the shift switch 27" has been moved to the other side of the circuit. Thus, the shift and set lines 35 and 33", respectively, are connected to the movable contacting elements of the switches, rather than to the common ends of the control means. In addition, the movable contacting element 25" of shift switch 27" is connected to a power common line 59. The negative side of the power supply, line 61, is connected to the common ends of the control means during operation, and the positive side of the power supply, line 63, is used only during the erase operation, which will be described infra.

The simultaneous shift register is provided with an input control relay which has a pair of control means 67 and 69, a movable contacting element 71, and stationary contacts 73 and 75. Input control relay 65 is controlled by an input reset switch 77 and an input release switch 79. Input reset switch 77 opens and closes a line to control means 67, while input release switch 79 opens and closes a line to control means 69 and, additionally, opens and closes a line to the movable contacting element 71 through diode 81. Movable contacting element 71 is also connected to the set bar or line 33 through diode 83. When the input control relay is in the proper position an input may be applied to the switch in the first set of switches A in the first stage by means of an input switch 85. Similarly, the input may be erased by energizing control means 7 of the switch in the first set of switches A in the first stage by input erase switch 87 through diode 89. Control means 7 of the switch in the first set of switches in the first stage is also connected to stationary contact 15 of the switch in the second set of switches B in the first stage through diode 91.

In operation, activation of input reset switch 77 causes control means 67 of the input control relay 65 to be energized and, therefore, place movable contacting element 71 in contact with stationary contact 73. With movable contacting element 71 in this position, an input may be provided through input switch 85. If input switch is actuated, the control means 9 of the switch in the first set of switches in the first stage will be energized through diode 83, movable contacting element 71, stationary contact 73, and the input switch 85. If it is desired to erase this signal before it is transmitted to the rest of the system, this may be accomplished by operation of the input erase switch 87. If it is desired to pass the information to the rest of the system the input release switch 79 will be actuated causing control means 69 to be energized and, thereby position movable contacting element 71 on stationary contact 75. This provides for energization of control means 17 or 19 of the switch in the second set of switches B in the first stage, through diode 81. If control means 19 is energized so that the movable contacting element 11 is positioned on stationary contact 15, the next shift operation, movement of movable contacting element 25' to stationary contact 31", will cause the control means 7 of the switch in the first set of switches A in the first stage to be energized through diode 91 and, therefore, be conditioned for the introduction of another signal. It will be noticed that the switches in the second set of switches B have an additional movable contacting element 93 and stationary contacts 95 and 97 added in each stage. These contacts may be connected as shown in the second stage of FIG. 3 to provide a coded readout signal.

In some cases it is desirable to completely erase any signals that may be present in the simultaneous shift register in order to introduce a completely new set of information. The erasing of the signals present in the simultaneous shift register is provided for by the erase switch 99. Ordinarily, the common ends of the control means of all the switches are connected to line 61 through lines 101 and 103. But it will be noticed that the control means 9 of the switches in the first set of switches A, after the first stage, are connected to line 103 rather than line 101. Actuation of the system erase switch insures that only the line 35 is energized through diode 105 and that line 103 is connected to positive line 63, rather than negative line 61. Thus, if the B switches are positioned so that the control means 7 of the A switches are energized, during the system. erase they will continue to be energized. However, if the B switches are positioned so that the associated A switches have the control means 9 energized, the actuation of the system erase switch causes a reverse current to flow in the magnetic control means 9 so that the movable contacting element 1 is moved to stationary contact 3, rather than stationary contact 5. This means that all of the movable contacting elements 1 are then positioned on sationary contact 3, so that after the system erase switch has been returned to its normal position the transferral of movable contacting element 25" of shift switch 27" will set all of the B switches with the movable contacting elements 11 positioned on stationary contacts 13, and the system erase is completed. In the special case of the control means 9 of the A switch in the second stage, a resistor 107 is connected from the control means to line 101 to permit the reverse current flow. This resistor is needed because of the presence of the diode to prevent inductive coupling interference.

In FIG. 4, a different type of shift register is shown. In this type of register the information is stacked up in the stages backwards from the output. Means are provided for preventing the introduction of new information into a stage, until that stage has been emptied of any previous information. The passing of information from one stage to the next succeeding stage may be the result of the fact that the next succeeding stage has not been given any information, or it may result from the fact that the information in the next succeeding stage has been passed on to a further succeeding stage, due to the removal of information from the output of the system. This type of shift register is denominated a sequence or storage shift register.

The main difference between the sequence shift register and the simultaneous shift register is that in the sequence shift register an additional channel, known as a steering channel, is necessary. The systems in both the steering channel and the information handling channel (or channels) is essentially that described in connection with FIG. 3. It should be noted that resistors 6 and 8 are indicated in the circuit. These resistors are included to dissipate the energy on coils 7 and 9, respectively, during the time that they are not energized. There are some slight changes, for instance, the shift switch 27" has been replaced with an AC switching arrangement 111. The AC shifting arrangement 111 includes a transformer 113 and diodes 115, 117 and 119. Thus, the switching is accomplished with half cycles of AC and a separate switching control is not necessary. Due to the more rapid rate of switching with a -cycle signal, the separate input reset switch utilized in the simultaneous shift register circuit of FIG. 3 has been i deleted also.

It may be seen from FIG. 4 that an additional movable contacting element 121 and stationary contacts 123 and 125 have been added to the switches in the second set of switches B in the steering channel. These switch elements are not the same as the read-out contacts 93, and 97 shown in FIG. 3. The common ends of the control means 7 and control means 9 of the switches in the first set of switches A in a stage are connected to the movable contacting element 121 of the switch in the second set of switches B in the same stage. All of the stationary contacts 123 are connected to line 127, which is the power line for the control means of the switches in the first set of switches A. The stationary contacts are connected to the movable contacting element 121 of the switches in the second set of switches B in the succeeding stage. The movable contacting element 121 is connected to the common ends of the control means 7 and 9 of the switches in the first set of switches A in both channels.

In operation, every input provided to the information handling channel produces energization of the control means 9 of the switch in the first set of switches A in the first stage of the steering channel. As the signal progresses down the steering channel it will only be entered in the A switches if the movable contacting element 121 of the B switch for that stage is positioned on the stationary contact 123, or if the movable contacting element 121 of a succeeding stage is contacting the stationary contact 123. As the information reaches the last stage, the movable contacting element 121 will be positioned on the stationary contact 125 for that stage. Thus, no succeeding information will be able to be stored in the last stage because it will not be possible to energize the control means 7 and 9 of that stage. Therefore, the next succeeding bit of information will be stored in the next preceding stage, which then will not be able to accept any more information. This continues on back until all of the stages are full or until the information in the last stage is removed, in which case the information in each of the preceding stages is then continued through the channel. The result of this operation is that the information is progressively stacked back towards the input in the information handling channel until the information in the last stage is removed, or the system is erased.

It was mentioned earlier that the additional contacts of the switches in the second set of switches B in the steering channel were not the same as the read-out contacts in the simultaneous shift register. However, in the information handling channel there are read-out contacts 93, 95 and 97 which do correspond to those in the simultaneous shift register. A divert point is shown in conjunction with the read-out contacts 93', 95 and 97. The divert point includes a control relay 129 which is nearly the same as the input control relay. At this divert point the series connection of the additional contacts for the switches in the second set of switches B is broken. With the series broken it means that an input in the steering channel at this stage will be prevented from being conveyed to the next succeeding stage. Control relay 129 includes a movable contacting element 131, and stationary contacts 133 and 135. If the limit switch 137 for the control relay 129 is actuated, movable contacting element 131 will be positioned on stationary contact 135 and the information in the switch of the second set of switches in the stage will be transferred to the next succeeding stage, if the read-out signal on 93' and 97 does not open normally closed contacts associated with lines 139 and 141. However, if the read-out signal does open the normally closed contacts, the information will not be transferred to the next stage, but will be diverted for the read-out device. If the signal is transferred to the next succeeding stage, return of the movable contacting element 131 to its position on sta tionary contact 133 will permit the signal to be transferred on through the channel.

An output release limit switch 143 is provided at the last stage. The output release limit switch 143 is the only control for the control means 7 of the switch in the first set of switches A in the last stage, If the output release limit switch 143 is actuated the movable contacting element 121 of the additional contacts on the switch in the second set of switches in the last stage is moved to stationary contact 123 to permit another signal to be inserted in the last stage. This permits information stacked toward the input in the information handling channel to be advanced toward the output.

A ring counter is depicted in FIG. 5. The ring counter is arranged in essentially the same manner as the basic shift register circuit of FIG. 1. The main dilference is the inclusion of reset switch 129, which has a movable contacting element and stationary contacts 133 and 135. During normal operation of the counter the movable contacting element 131 is contacting stationary contact 133. However, in the operation of the ring counter it is frequently necessary to reset the arrangement so that a new counting sequence may be started. This function is accomplished by switch 129 in such a manner than when the movable contact element 131 is transferred to stationary contact 135 the circuit is reset, or erased. The one difference between this operation and the complete erase is that the movable contacting element 1 of the switch in the first set of switches A in the first stage is positioned on stationary contact 5 rather than stationary contact 3. This insures that an input will generate a new sequence of counter pulses, The remainder of the movable contacting elements 1 are positioned on the stationary contacts 3, or the normal erase position. The reset operation is achieved by putting current through diodes 137 from the stationary contact 135 of switch 129. The line connected to stationary contact 135 may be conveniently referred to as a reset bus. Diodes 137 are connected to a particular control means of the switches in the second set of switches B.

To provide the ring counter operation it is necessary to connect the stationary contacts 13 and 15 of the switch in the second set of switches B in the last stage to the control means 7 and 9, respectively, of the switch in the first set of switches A in the first stage. This closed loop arrangement provides for a successful ring counter opera tion. During the ring counting operation, it is generally desirable to have some indication of the presence of a particular signal in each stage. In the present circuit output signals are obtained from the outputs 139, which are connected to the stationary contact of the switch in the first set of switches A in each stage. Thus, the ring counter operation is complete.

FIG. 6 shows another embodiment of a circuit arrangement utilizing double-throw reed switches. This circuit has an operation similar to that of the standard flip-flop circuit and has been characterized as a flip-flop control unit. In the basic single stage flip-flop control unit there is contained a switch from the first set of switches A and a switch from the second set of switches B. Each of the contacts and control means of these switches have been designated the same as in the shift register of FIG, 1. Using these numerals, the stationary contact 3 of the switch in the first set of switches A is connected to the control means 17 of the switch in the second set of switches B. Similarly, the stationary contact 5 is connected to control means 19. The connections of the stationary contacts of the switch in the second set of switches B is transposed from the connections utilized in the basic shift register. Power for the circuit is obtained from a DC power supply providing the energy through lines 141 and 143. A selected control means of the switch in the first set of switches A and a selected control means of the switch in the second set of switches B are alternately energized, with the alternate energization controlled by the pulse switch 145. Pulse switch 145 has a movable contacting element 147 and stationary contacts 149 and 151. If the movable contacting element 11 of the switch in the second set of switches is on stationary contact 15, control means 7 of the switch in the set of switches A will be energized and cause the movable contacting element 1 to be positioned on stationary contact 3. If the pulse switch movable contacting element 147 is then moved to stationary contact 151, control means 17 of the switch in the second set of switches B will be energized and cause the movable contacting element 11 to be positioned on stationary contact 13. Return of the pulse switch movable contacting element 147 to stationary contact 149 will then cause energization of control means 9' of the switch in the first set of switches A. Thus, the movable contacting element 1 will be positioned on stationary contact 5. Another movement of the movable contacting element 147 to stationary contact 141 will energize control means 19 of the switch in the second set of switches B and return this switch to its original position. Another sequence of the operation just discussed may then be undertaken. Energization of control means 19 also permits the obtaining of an output signal from the output 153. This output signal may be utilized to produce a circuit arrangement utilizing a series of these units. The output will be produced after every second input pulse so that a fiipflop type of operation is obtained. For a series arrangement of these units a signal is taken from 155 to be applied to the movable contacting element 11 of a switch in the second set of switches B in the next succeeding stage.

In FIG. 7 an arrangement utilizing a series of the units shown and described in connection with FIG. 6 is illustrated. In this figure the individual units are arranged to form a binary counter. The binary counter arrangement is achieved by taking an output pulse from the output 153 and applying it to the movable contacting element 1 of the switch in the first set of switches A in the next stage. Also, the pulse for the movable contacting element 11 of the switch in the second set of switches B in the second stage is obtained from the output 155, This means that a pulse is applied to the movable contacting elements of the switches in the second stage only after two pulses have been applied to the corresponding movable contacting elements in the first stage. Similarly, each succeeding stage is connected with the movable contacting element of the switch in the first set of switches of the succeeding stage connected to the output 153 and the movable contacting element 11 of the switch in the second set of switches in the succeeding stage next to the output 155 of the preceding stage. Thus, a pulse is applied to the movable contacting element 1 of the switch in the first set of switches in the third stage after two pulses have been applied to the movable contacting element 1 of the switch in the first set of switches in the second stage. But since two input pulses are applied to the first stage before a pulse is obtained at the second stage, this means that a total of four initial input pulses have to be applied to the first stage before a pulse is obtained at the third stage. In the same manner it would take eight initial input pulses at the first stage before a pulse would be obtained at the fourth stage. Thus, the number of initial input pulses needed before a pulse is obtained at a stage would be twice the number of initial input pulses needed to produce a pulse in the preceding stage. Thus, a binary counter is formed with the output of each stage corresponding to a digit in a numerical system based upon the number 2.

FIG. 8 illustrates an add and subtract count register. This count register is based upon the basic shift register circuit of FIG. 1, rather than the flipfiop unit of FIG. 6, but is arranged to perform the simple mathematical functions of additioniand subtraction. These functions are achieved by using an arrangement having both forward and backward shifting characteristics, such as the arrangement described in connection with FIG. 2. However, rather than utilizing the additional control coils such as 4-5 and 47 in FIG. 2, this embodiment relies on the addition of a movable contacting element 57 and stationary contacts 159 and 161 in connection with the switch in the second set of switches. With this arrangement the stationary contact 159 is connected to the control means 7 of a switch in the first set of switches in the preceding stage and the stationary contact 151 is connected to the control means of the same switch.

During the addition phase the operation of the circuit is that described in connection with the drawing of FIG. 1. During the subtract phase a subtract signal is inserted into the circuit which essentially erases the signal in the last stage of the unit. With the presence of additional subtract pulses this erase operation extends backward to erase the signal in each preceding stage. Thus, addition and subtraction functions are obtained.

In the description of the various embodiments of this invention, broad terms have been used in the description of the reed switches. The term movable contacting element has been used to describe the movable contact of the reed switches. In specific terms this movable contacting element may be a deflectable reed. Similarly, the broad term control means has been used quite extensively to define the means used to control the position of the deflectable reed. These control means would generally be an electromagnetic coil, but would not be limited to such a definition. Also, the term biasing means has been used to define the arrangement for holding the deflectable reed in the position in which it is last placed. In practice, the biasing means would ordinarily be a permanent magnet arrangement, but could be some other type of arrangement. All of these particulars are discussed in detail in US. Patent No. 3,166,652, assigned to the same assignee as the present invention.

Although the invention has been described with respect to certain specific embodiments, it will be appreciated that modifications and changes may be made by those skilled in the art without departing from the basic teachings of the invention. Therefore, it is desired not to limit the following claims to the specific embodiment shown, but to cover all modifications and changes within the spirit and scope of the invention.

What is claimed as new and desired to be secured by Letters Patent of the United States is:

1. An electrical circuit comprising: a first set of switches and a second set of switches; a switch in said first set of switches and a switch in said second set of switches, each of said switches having a movable contact element positionable in either of two contacting positions; first and second control means for each of said switches, energization of said first control means causing said movable contacting element to be forceably transferred to a first of said contacting positions, energization of said second control means causing said movable controlling element to be forceably transferred to a second of said contacting positions; biasing means for retaining each of said movable contacting elements in whichever of said contacting positions it is positioned until it is forceably transferred to the other of said positions; means for alternately energizing a control means of a switch in said first set of switches and a control means of a switch in said second set of switches; means connecting said set of switches, whereby the energization of a particular control means of a switch in said first set of switches is determined by the position of the contacting element of a switch in said second set of switches, and the energization of a particular control means of a switch in said second set of switches is determined by the position of the contacting element of a switch in said first set of switches.

2. An electrical circuit comprising: a first set of doublethrow reed switches and a second set of double-throw reed switches; a switch in said first set of double-throw reed switches and a switch in said second set of double-throw reed switches; each of said switches having a defiectable reed positionable in either of two contacting positions; first and second magnetic control means for each of said switches, energization of said first magnetic control means causing said defiectable reed to be forceabiy transferred to a first of said contacting positions, energization of said second magnetic control means causing said deflectable reed to be forceably transferred to a second of said contacting positions; magnetic biasing means for retaining each of said deflectable reeds in whichever of said contacting positions it is positioned until it is forceably transferred to the other of said positions; means for alternately energizing a magnetic control means of a switch in said first set of doublethrow reed switches and a magnetic control means of a switch in said second set of doublethrow reed switches; means connecting said sets of switches, whereby the energization of a particular magnetic control means of a switch in said first set of switches is determined by the position of the deflectable reed of a switch in said second set of double-throw reed switchs, and the energization of a particular magnetic control means of a switch in said second set of switches is determined by the position of the deflectable reed of a switch in said first set of double-throw reed switches.

3. A shift register comprising: a first set of switches and a second set of switches; a plurality of consecutively arranged information shifting stages, each stage including one switch in said first set of switches and one switch in said second set of switches, each of said switches having a movable contacting element and a pair of stationary contacts; said movable contacting element contacting a first one of said stationary contacts in a first contacting position and contacting the other of said stationary contacts in a second contacting position; first and second control means for each of said switches, encrgization of said first control means causing said movable contacting element to be forceably transferred to said first contacting position, energization of said second control means causing said movable contacting element to be forceably transferred to said second contacting position; biasing means for retaining each of said movable contacting elements in whichever of said contacting positions it is positioned until it is forceabiy transferred to the other of said positions; means for alternately energizing a particular control means of each of the switches in said first set of switches and a particular control means of each of the switches in said second set of switches; means connecting a stationary contact of a switch in said first set of switches to a control means of the switch in said second set of switches in the same stage; and means connecting a stationary contact of a switch in said second set of switches to a control means of the switch in said first set of switches in the next succeeding stage, whereby the energization of a particular control means of a switch in said second set of switches is determined by the position of the contacting element of the switch in said first set of switches in the same stage, and the energization of a particular control means of a switch in said first set of switches is determined by the contacting element of the switch in said second set of switches in the preceding stage.

4. A shift register as recited in claim 3 wherein: said switches are double-throw reed switches; said movable contacting elements are defiectable reeds; said control means are electromagnetic-ally energized coils; and said biasing means are permanent magnets.

S. A shift register as recited in claim 3 wherein said means for alternately energizing a particular control means of each of the switches in said first set of switches and a particular control means of the switches in said second set of switches comprises a supply of DC power and a first shift switch, said first shift switch positionable in two contacting positions to provide said alternate energization; the shift register further including additional first and second control means for the switches of said first set of switches, said additional control means being connected to the stationary contacts of the switch in said second set of switches in a succeeding stage; a second shift switch for alternately energizing a particular one of the additional control means of the switches in said first set of switches and a particular control means of the switches in said second set of switches, whereby the operation of said first shift switch causes forward shifting of the information in said shift register and the operation of said second shift switch causes backward shifting of the information of said shift register.

6. A shift register as recited in claim 3 and further including; an output load connected in parallel with a particular control means of a switch in said second set of switches, said output load being energized concurrently with the control means of the switch in said second set of switches with which it is connected in parallel.

7. A shift register as recited in claim 3 wherein one end of each of said control means of each switch in said second set of switches is joined to the others in a common connection, the shift register further comprising: an alternating current power supply having one side connected to the common connection of the control means of the switches in said second set of switches; each stage of said shaft register including an indicating breakdown device connected between the other side of said alternating current power supply and one of the stationary contacts of a switch in said first set of switches, whereby the positioning of the movable contacting element of said switch in said first set of switches on the selected station ary contact initiates breakdown of said breakdown device and causes an indicating signal to be produced.

8. A shift register as recited in claim 7 wherein said breakdown device is a neon lamp.

9. A simultaneous shift register comprising: a first set of switches and a second set of switches; an information handling channel including a first stage and a plurality of consecutive succeeding stages; each stage including a switch in said first set of switches and a switch in said second set of switches, each switch having a movable contacting element and a pair of stationary contacts; said movable contacting element contacting a first one of said stationary contacts in a first contacting position and contacting the other of said stationary contacts in a second contacting position; first and second control means for each of said switches, energization of said first control means causing said movable contacting element to be forceably transferred to a first of said contacting positions, energization of said second control means causing said movable contacting element to be forceably transferred to a second of said contacting positions; biasing means for retaining each of said movable contacting elements in which ever of said contacting positions it is positioned until it is forceably transferred to the other of said positions; means for separately controlling the energization of a control means of each of the switches in said first stage; means for alternately energizing a control means in each of the switches in said first set of switches in stages after said first stage and a control means in each of the svsn'tches in said second set of switches in stages after said first stage; means connecting a stationary contact of a switch in said first set of switches to a control means of the switch in said second set of switches in the same stage; and means connecting a stationary contact of a switch in said second set of switches to a control means of the switch in said first set of switches in the next succeeding stage, so that the energization of a particular control means of a switch in said second set of switches is determined by the position of the contacting element of the switch in said first set of switches in the same stage, and the energization of a particular control means of a switch in said first set of switches is determined by the position of the contacting element of the switch in said second set of switches in the preceding stage, whereby said alternate energization causes information inserted in said first stage to be transferred to successive stages, with the information stored in any of said stages being simultaneously transferred to the next succeeding stage.

10. A simultaneous shift register as recited in claim 9 wherein: said switches are double-throw reed switches; said movable contacting elements are defiectable reeds; said control means are electromagnetically energized coils; and said biasing means are permanent magnets.

11. A simultaneous shift register as recited in claim 9 wherein said means for individually controlling said first stage comprises: a double-throw reed input switch having a movable contacting element and a pair of stationary contacts, said movable contacting element having first and second contacting positions; first and second control means for placing said movable contacting element in said first and second contacting positions respectively; biasing means for retaining said movable contacting element in the contacting position in which it is last placed until forceably transferred to the other of said contacting positions; means for energizing said first control means to place said movable contacting element in said first contacting position; means for energizing said second control means to place said movable contacting element in said second contacting position; means connecting a first of said stationary contacts to the movable contacting element of the switch in said first set of switches in said first stage; and means connecting the other of said stationary contacts to the control means of the switch in said first set of switches in said first stage, whereby energization of said second control means permits information to be entered into the switch in said first set of switches in said first stage and energization of said first control means provides for said information to be transferred to the switch in said second set of switches in said first stage.

12. A simultaneous shift register as recited in claim 9 wherein a first side of each of said control means is connected to a stationary contact of a switch from the other set of switches; the other side of each of the control means of the switches in said second set of switches and the other side of said first control means of the switches in said first set of switches connected to a first line, the other side of said second control means of the switches in said first set of switches connected to a second line, said first and second lines connected together and connected to a source of power during normal operation; erase means comprising a system erase switch having an erase position and a non-erase position when placed in erase position said erase switch disconnects said first line from said second line and connects said second line to a power supply of an opposite polarity than that connected to said first line, when placed in said erase position said erase switch also disconnects said alternate energizing means and connects a constant energizing means to said movable contacting element of each of the switches in said second set of switches; means for placing said system erase switch in its erase position and for returning it to its non-erase position, whereby all of the successive stages of the register are erased.

13. A simultaneous shift register as recited in claim 9 and further including: a second set of stationary contacts associated with the control means of each of the switches in said second set of switches, said second set of stationary contacts providing a coded read-out for each stage.

14. A sequence shift register comprising: a first set of switches and a second set of switches; an information handling channel and a steering channel; said information handling channel including a first stage and a plurality of consecutive succeeding stages, each stage including a switch in said first set of switches and a switch in said second set of switches, each switch having a movable contacting element and a pair of stationary contacts; said steering channel including a first stage and a plurality of consecutive succeeding stages, each stage including a switch in said first set of switches and a switch in said second set of switches, each switch in said first set of switches in said steering channel having a movable contacting element and a pair of stationary contacts, each switch in said second set of switches in said steering channel having a first and a second movable contacting element and a pair of stationary contacts associated with each movable contacting element; each of said movable contacting elements in each of said switches contacting a first one of said associated stationary contacts in a first contacting position and contacting the other of said associated stationary contacts in a second contacting position; first and second control means for each of said switches, energization of said first control means causing said movable contacting elements associated with that switch to be forceably transferred to said first contacting position, energization of said second control means causing said mov able contacting elements associated with that switch to be forceably transferred to said second contacting position; biasing means for retaining each of said movable contacting elements in whichever of said contact positions it is positioned until it is forceably transferred to the other of said positions; means for alternately energizing a control means of each of the switches in said first set of switches and a control means of each of the switches in said second set of switches; means connecting said set of switches in each of said channels in such a manner that the energization of a particular control means of a switch in said second set of switches is determined by the position of a contacting element of the switch in said first set of switches in the same stage, and the energization of a particular control means of a switch in said first set of switches is determined by the position of a contacting element of the switch in said second set of switches in the preceding stage; means connecting said second movable contacting element and its associated stationary contacts in said second set of switches in said steering channel to said information handling channel in such a manner that information placed in said information handling channel is conveyed to the last stage in said channel and subsequent information is stored in stages toward the input of said channel, said last-named means and said second movable contacting element and associated stationary contacts in said steering channel prevent the introduction of new information into a stage of said information handling channel until the information already contained in that stage has been shifted toward the output.

15. A sequence shift register as recited in claim 14 wherein: all of said switches are double-throw reed switches; said movable contacting elements are deflectable 15 reeds; said control means are electromagnetically energized coils; and said biasing means are permanent magnets.

16. A sequence shift register as recited in claim 14 wherein: said means for alternately energizing a control means of each of the switches in said first set of switches and a control means of each of the switches in said second set of switches is an AC source connected to said control means through a rectifier circuit.

17. A ring counter comprising: a first set of switches and a second set of switches; each switch in each set of switches having a movable contacting element and a pair of stationary contacts; said movable contacting element contacting a first one of said stationary contacts in a first contacting position and contacting the other of said stationary contacts in a second contacting position; first and second control means for each of said switches, energization of said first control means causing said movable contacting element to be forceably transferred to said first contacting position, energization of said second control means causing said movable contacting element to be forceably transferred to said second contacting position; biasing means for retaining each of said movable contacting elements in whichever of said contacting positions it is positioned until it is forceably transferred to the other of said positions; means for alternately energizing a control means of the switches in said first set of switches and a control means of the switches in said second set of switches; a plurality of stages, each stage including one switch from said first set of switches and one switch from said second set of switches; means connecting a stationary contact of the switch in said second set of switches in the last stage of said plurality of stages to a control means of the switch in said first set of switches in the first stage of said plurality of stages; means connecting a stationary contact of a switch in said first set of switches to a control means of the switch in said second set of switches in the same stage; and means connecting a stationary contact of a switch in said second set of switches to a control means of the switch in said first set of switches in the next succeeding stage, the energization of a particular control means of a switch in said first set of switches being determined by the position of the contacting element of a switch in said second set of switches in the preceding stage, and the energization of a particular control means of a switch in said second set of switches being determined by the position of the contacting element of the switch in said first set of switches in the same stage; and means for obtaining an output signal at each stage.

18. A ring counter as recited in claim 17 wherein: said switches are double-throw reed switches; said movable contacting elements are deflectable reeds; said control means are electromagnetically energized coils; and said biasing means are permanent magnets.

19. A ring counter as recited in claim 17 and further including: rectifier means connecting one of said control means of the switches in said second set of switches to a reset bus, said reset bus being normally de-energized; means for de-energizing said normal energizing means and energizing said reset bus when it is desired to reset the stages of the ring counter.

20. A flip-flop unit comprising: a first switch and a second switch, each switch having a movable contacting element and a pair of stationary contacts; said movable contacting element contacting a first one of said stationary contacts in a first contacting position and contacting the other of said stationary contacts in a second contacting position; first and second control means for each of said switches, energization of said first control means causing said movable contacting element to be forceably transferred to said first contacting position, energization of said second control means causing said movable contacting element to be forceably transferred to said second contacting position; biasing means for retaining each of said movable contacting elements in whichever of said contact positions it is positioned until it is forceably transferred to the other of said positions; means for alternately energizing a particular control means of said first switch and a particular control means of said second switch; means connecting said first stationary contact of said first switch to said first control means of said second switch and said second stationary contact to said second control means; and means connecting said first stationary contact of said second switch to said second control means of said first switch and said second stationary contact to said first control means, the connections from the stationary contacts of said second switch to the control means of said first switch being transposed so that said movable contacting element of said first switch is always transferred to the other of its contacting positions upon energization of a control means of said first switch.

21. A flip-flop unit as recited in claim 20 wherein: said switches are double-throw reed switches; said movable contacting elements are defiectable reeds; said control means are electromagnetically energized coils; and said biasing means are permanent magnets.

22.. A binary counter comprising: a plurality of units as described in claim 20; an output pulse derived from said unit when said movable contacting element of said first switch is in a predetermined one of said contacting positions, means connecting said output of each unit to the movable contacting element of said first switch in the succeeding unit; additional means connecting a predetermined stationary contact of said second switch in each unit to the movable contacting element of said second switch in the succeeding unit, whereby an output pulse is obtained from said first unit after every two input pulses, an output pulse is obtained from said second unit after every four input pulses, an output pulses is obtained from said third unit after every eight input pulses, and succeeding units produce a pulse after a number of input pulses corresponding to two times the number of input pulses that it takes to produce an output from the next preceding stage.

23. An add and subtract count register comprising: a first set of switches and a second set of switches, a plurality of consecutively arranged information shifting stages, each stage including a switch in said first set of switches and a switch in said second set of switches, each switch in said first set of switches having a movable contacting element and a pair of stationary contacts, each switch in said second set of switches having a first and a second movable contacting element and a pair of stationary contacts associated with each movable contacting element; each of said movable contacting elements contacting a first one of said associated stationary contacts in a first contacting position and contacting the second of said associated stationary contacts in a second contacting position; first and second control means for each of said switches, energization of said first control means causing said movable contacting elements associated with that switch to be forceably transferred to said first contacting position, energization of said second control means causing said movable contacting elements associated with that switch to be forceably transferred to said second contacting position; biasing means for retaining each of said movable contacting elements in whichever of said contacting positions it is positioned until it is forceably transferred to the other of said positions; means for alternately energizing said control means of each of the switches, said first set of switches and a control means of each of the switches in said second set of switches; means connecting said first and second stationary contacts of the switches in, said first set of switches to said first and second control means of the switch in said second set of switches in that stage respectively, to govern which of the control means of the switch in said second set of switches will be energized; means connecting said first and second stationary contacts of one set of contacts of the switches in said second set of switches to said first and second control means of a switch in said first set of switches in a succeeding stage respectively, to govern which of said control means of said switch in said first set of switches will be energized during an add operation; means connecting said first and second stationary contacts of said second set of contacts of the switch in said second set of switches to said first and second control means of a switch in first set of switches in a preceding stage respectively, to govern which of said control means of said switch in said first set of switches will be energized during a subtract operation, whereby an add signal is propagated forward from the input end and a subtract signal is propagated backward from the output end.

24. An add and subtract count register as recited in claim 23 wherein: said switches are double-throw reed switches; said movable contacting elements are deflectable reeds; said control means are electromagnetically energized coils; and said biasing means are permanent magnets.

References Cited UNITED STATES PATENTS 3,042,900 7/1962 Werts 340-168 3,217,297 11/1965 Delugeau 340-168 MAYNARD R. WILBUR, Primary Examiner. G. J. MAIER, Assistant Examiner. 

